Single-step chitosan functionalized membranes for heparinization

Hemodialysis is an established life-sustaining treatment for blood purification. However, the limited hemocompatibility of the applied dialysis membranes makes additional heparin dosing to the patient inevitable. This work presents facile methods using chitosan for successful heparinization of membranes. First, a chitosan coating on commercial dialysis membranes and subsequent heparinization is shown. The resulting membranes exhibit significant charge differences and a considerable increase in pure water permeance. To overcome time-consuming and multi-step coating procedures, we demonstrate the single-step fabrication of promising chitosan-blended flat sheet and hollow fiber membranes. Highlights of these membranes are their significant surface charge differences, strong antifouling properties and their excellent hemocompatibility, which thrombin–antithrombin complex, complement and platelet activation measurements show. Furthermore, the heparinized surface increases the pure water permeance of the chitosan-blended membranes. The highly promising results of the heparinized chitosan-blended membranes enable their use in hemodialysis. Overall, the chitosan-blended membranes present another example in which single-step fabrication successfully replaces complex multi-step coating procedures.